1. Field of the Invention
The invention relates to bearings and, more particularly, relates to a straddle bearing for an output shaft of a power takeoff assembly.
2. Discussion of the Related Art
Power takeoff assemblies (PTOs) are well known and are employed to transmit torque from a prime mover such as an internal combustion engine to a remote device. Such assemblies typically employ a driven output shaft which is connected to a clutch and which has a drive member such as a sheave or a sprocket mounted thereon for transmitting torque to a driven member such as a sheave or sprocket of the remote device via a belt or chain. The shaft is in most instances cantilevered from the rear end of the PTO clutch housing. This may cause problems when side loads are applied to the shaft during operation because such loads may be transmitted to the engine flywheel, thus increasing wear on the assembly. This problem becomes more pronounced when relatively long shafts are employed and/or when the PTO is subject to heavy side loads.
One way to reduce loads imposed on shafts, flywheels, etc. is to support the sheave or other drive member at a point aft of the outside of the clutch housing. A device supporting a drive member in this manner is disclosed in U.S. Pat. No. 3,587,331 which issued to Moss on Jun. 28, 1971. The device disclosed by Moss employs a tubular housing having a front end fixed to the rear surface of the clutch housing and receiving an output shaft in a central bore formed therethrough. A sheave is rotatably mounted via bearings on the cylindrical exterior of the housing, and is connected to the shaft by a gear which is splined to the free end of the shaft. The tubular housing absorbs at least some of the radial loads imposed on the sheave so that such loads are not imposed on the shaft and the flywheel.
The device disclosed in the Moss patent exhibits several drawbacks and disadvantages. For instance, the sheave must be specially designed and constructed so as to receive the bearings for supporting the sheave on the tubular housing and so as to mesh with the drive gear attached to the shaft. This significantly increases the assembly's complexity, thus increasing its cost and potentially decreasing its reliability. Moreover, the entire or substantially the entire housing is in all instances cantilevered from the rear of the clutch housing and associated support, thus limiting the load bearing capacity of the housing. Moreover, the device disclosed by Moss is incapable of receiving auxiliary sheaves or other drive members, and thus is capable of driving only one remote device at any given time.